Plants are a natural warehouse of bioactive compounds. A difficulty in accessing this abundant diversity of compounds lies in the separation of the various components. Isoflavones are an example of an interesting class of phenolic-containing plant flavonoid compounds that are believed to have a number of beneficial health effects on mammals. For example, isoflavones have been suggested to provide a beneficial effect on the symptoms experienced by menopausal and peri-menopausal women. Currently 15% of menopausal women are on Hormone Replacement Therapies (HRT) that employ animal estrogens. HRT products derived from animal estrogens are highly potent and activate all estrogen receptors. This potency is correlated with an increased risk of breast cancer and other complications. Since plant isoflavones have a lower affinity to the estrogen receptor, they may be preferred to animal estrogens for some uses. In addition, some research has indicated that isoflavones may even prevent or retard certain cancers, such as breast and prostate cancers, as well as have serum cholesterol-lowering effects.
Despite the beneficial effects associated with plant isoflavones, many individuals have not increased their intake of isoflavones, particularly those available from soy foods, because the variety of soy based foods in many countries have been limited and because many find the flavor and colors of soy foods bitter and unappetizing. In addition, earlier methods for isolating isoflavones often resulted in isoflavones compositions of reduced water solubility and thus limited applicability for incorporation into foodstuffs and beverages. Thus, it would be desirable to provide methods for isolating isoflavones from a variety of plant materials with improved purity, color, flavor, texture, and solubility to promote the incorporation of these beneficial nutrients in a variety of food, beverage, dietary supplement, and pharmaceutical products.